Newswise — The American Cancer Society just published a paper reporting that while breast cancer incidence rates for 2008-2012 were similar for black and white women, death rates were 42% higher for black women [DeSantis, 2015]. The factors suggested to explain the disparity in mortality rates included difference in stage at diagnosis, obesity, comorbidities, tumor characteristics, as well as access, adherence, and response to treatments.

However, a study in California found that body mass index did not affect survival rates for black American women [Kwan, 2014].

No mention of the role of vitamin D in reducing risk of breast cancer and increasing survival after diagnosis was made in the American Cancer Society paper.

Also, women who live in the sunny states have much lower breast cancer mortality rates than those who live in the cloudy states in the north [John, 2007]. Solar ultraviolet-B exposure is the primary source of vitamin D for most people.

A review of differences in cancer survival rates found that after consideration of stage at diagnosis, socioeconomic status, and treatment, black Americans had about 25% increased mortality rates for most types of cancer [Grant, 2012]. The difference was consistent with the fact that black Americans have 25-hydroxyvitamin D concentrations about 40% lower than white Americans since their dark skin reduces the production rate of vitamin D in the sun.

A paper from the Roswell Park Cancer Center concluded "The relationship of vitamin D with breast cancer risk may be subtype-specific, with emerging evidence of stronger effects of vitamin D for more aggressive breast cancer, particularly in women of African ancestry." [Yao, 2013].

Further evidence that vitamin D concentration affects cancer survival rates comes from a nine-year study in Norway. The hazard ratio for the nine-year all-cause survival after diagnosis of breast cancer was much lower (63% lower) for women with higher 25-hydroxyvitamin D concentrations [Tretli, 2012].

Based on results in the peer-reviewed scientific literature [Baggerly, 2015], cancer incidence and mortality rates could be greatly reduced if everyone had 25-hydroxyvitamin D concentrations above 40 ng/mL.An all-source vitamin D3 input of 4000 IU/d ensures that 50% of the population achieves 25-hyderoxyvitamin D concentrations above 40 ng/mL (8000 IU/d is needed for 90% of the population). [Garland, 2011]. The benefits of sunlight and vitamin D for public health were discussed at a seminar held by GrassRootsHealth.net in December 2014 [Baggerly, 2015].